1. Field of the Invention
The present invention relates to a thin film transistor and a display substrate having the same. More particularly, the present invention relates to a thin film transistor applied to an active type display device and a display substrate having the thin film transistor.
2. Description of the Related Art
In general, a display substrate is applied to a flat panel display device, e.g., a liquid crystal display device, an organic electroluminescent display device, etc., to realize lightweight and thin thickness of the flat panel display device.
The display substrate includes pixels arranged in a matrix form and displays an image by applying a source voltage to each pixel. The display substrate includes gate lines and data lines crossing the gate lines, and the gate lines are insulated from the data lines by an insulating layer. Each gate line is connected to a thin film transistor disposed in each pixel and applies a signal to the thin film transistor to control the thin film transistor. The thin film transistor switches a voltage applied to a corresponding pixel of the pixels. In addition, each data line applies the voltage to the corresponding pixel of the pixels.
Meanwhile, source and drain electrodes of the thin film transistor and the data line are formed of a conductive material, such as aluminum, copper, etc. However, aluminum and copper are vulnerable to corrosion and oxidation.